THE FLOWER AND THE BEE 



The flower is securely anchored to the bottom of the stream 

 by a long stem. At first the opening in the bud is no larger 

 than a bee's body, and the chamber within offers a dry and 

 snug shelter amid the waves. It may be truly called a haven of 

 refuge. Directly below the entrance is a broad, many-rayed, 

 crown-shaped stigma, as in the poppy. The petals are thick, 

 wedge-shaped bodies which are orange-yellow on the outer 

 side near the top, where they freely secrete nectar. Under a 

 microscope both large and minute drops can readily be seen. 

 The stamens are indefinite in number; and revelling in the 

 pollen, their bodies completely covered, there is a large and 

 lively company of small flies called Hilar a atra. Less common 

 are two beetles, Donacia piscatrix and Donacia rufa; but what 

 chiefly interests us is a small bee, Halictus nelumbonis, or the 

 water-lily bee. This bee in this locality is never found on 

 any other flower, but elsewhere it is met with on other species 

 of the water-lily family, or Nymphceaceoe. Since, however, it 

 confines its visits to the water-lily family it is an oligotropic 

 bee, and the only species of the great genus Halictus that is 

 known to behave in this way. 



But in Andrena this is a common phenomenon; for instance, 

 in Washington County, Wis., according to Graenicher, 24 of 

 the 47 indigenous species of Andrena are oligotropic. This is 

 the largest genus of North American bees. They are some- 

 times called ground-bees, since they build branched tunnels 

 8 or 10 inches deep in the soil of sandy pastures and hillsides. 

 A part of the species are vernal or fly in springtime, while a 

 part are autumnal and fly only in autumn. They provision 

 their cells with balls of "bee-bread," about the size of a garden- 

 pea, composed of pollen moistened with nectar. An egg is 

 laid on the top of the mass of bee-bread, and the cell is then 

 closed. 



108 



